"A phonologist ignores phonetics at his own peril," remarks Professor Lehiste, whose work in acoustic phonetics and in historical and descriptive phonology over the past decade has resulted in this important experimental study of the linguistic function of suprasegmentals. The author assembles and summarizes what is currently known about the phonetic nature of suprasegmentals and evaluates the available evidence from the point of view of linguistic theory. She describes observed linguistic facts, seeks to explain them, and attempts to set up predictions. The book contains a great deal of painstakingly gathered evidence for the existence of speech patterns whose domain is larger than a segment and which, the author states, should form a part of linguistic theory. Suprasegmental features are either listed as the set of features consisting of pitch, stress, and quantity or defined as features whose domain extends over more than one segment. In American linguistics, the author points out, the term is used more or less synonymously with prosodic features. She contends that neither definition is complete and intends in this research to provide a more fully satisfying description of these complex and elusive phenomena. The emphasis of Professor Lehiste's work is on the production and perception of suprasegmental features. She attempts to identify the phonetic conditioning factors within which the features may be manifested, then considers their linguistic functions at the word level and at the sentence level. Foe convenience, a chart immediately following the introductory chapter illustrates the scheme of presentation followed throughout the book. Chapter 2 deals with duration and its linguistic function. It considers physiological mechanisms involved in producing quantity phenomena, their physical (acoustic) manifestation, the perceptual correlates of quantity, various phonetic phenomena connected with quantity, and the linguistic function of quantity. Chapter 3 considers the suprasegmental elements of pitch, tone, and intonation. "Tonal features" is used here as a general term referring to all aspects of the linguistic use of fundamental frequency and its physical and perceptual correlates. Chapter 4 deals with the most elusive of the suprasegmental features, stress. The author discusses some of the physiological correlates of linguistic stress which have been established by experimental techniques over the past 15 years. In a concluding chapter Professor Lehiste evaluates the findings and considers their potential contribution to linguistic theory. Professor Lehiste has provided substantial groundwork for further research in phonetics, including the investigation of suprasegmental sandhi effects and the role of suprasegmentals in morphophonemic rules.